Reporter's way to reach source (4)
I believe the answer is:
root
'source' is the definition.
(both can mean the origin of something)
'reporter's way' is the wordplay.
'reporter's' indicates a 'sounds like' (homophone) clue (report can mean to speak something aloud).
'way' becomes 'route' (route is a kind of way).
'route' is a homophone of 'ROOT'.
'to reach' acts as a link.
(Other definitions for root that I've seen before include "Rummage for plant base" , "essential nature" , "Part of plant under the ground" , "Organ that anchors plants in the ground" , "Derivation" .)